How did monsoon flooding affect the development of civilizations in the Indus River Valley?

The slow eastward migration of monsoons across the Asian continent initially supported the formation of the Harappan civilization in the Indus valley by allowing production of large agricultural surpluses, then decimated the civilization as water supplies for farming dried up

Winter monsoons bring dry air. Spring monsoons bring moisture from the ocean. The monsoons are unpredictable. Too little rainfall can lead to starvation while too much rainfall can cause flooding and wipe out villages.

The slow eastward migration of monsoons across the Asian continent initially supported the formation of the Harappan civilization in the Indus valley by allowing production of large agricultural surpluses, then decimated the civilization as water supplies for farming dried up, researchers reported Monday.